“We are pleased to have received orphan drug designation for CBD to treat infantile spasms, a catastrophic form of childhood epilepsy,” said Michael L. Babich, President and Chief Executive Officer. “If successful, our CBD product could offer certain children the potential to attain seizure control and to potentially achieve an improved level of development. It is also an opportunity to have a significant, positive impact in the lives of these unfortunate children and their families. We are updating our current IND to initiate a clinical trial at UCLA.”

Raman Sankar, MD, PhD, lead investigator for Insys’ planned CBD trial for the treatment of IS with Dr. Shaun Hussain at UCLA, stated, “The population that we are studying in this clinical trial is infants who have failed currently approved therapies for a debilitating disease associated with detrimental effects on their short- and long-term development. I am pleased to be leading this investigation of CBD which, if successful, could offer a new treatment option for these infants for whom there are limited or no currently available therapies.”

Orphan drug designation is granted by the FDA Office of Orphan Products Development to novel drugs or biologics that treat rare diseases or conditions affecting fewer than 200,000 patients in the U.S. The designation provides the drug developer with a seven-year period of U.S. marketing exclusivity upon approval, as well as certain financial incentives that can help support its development.

Insys expects that its new, DEA-inspected facility in Round Rock, Texas, will enable it to manufacture ample quantities of CBD for its research and commercial plans.

About Pharmaceutical CBD Cannabidiol (CBD) is one of at least 60 active cannabinoids identified in cannabis. CBD is considered to have a wider scope of medical applications than tetrahydrocannabinol (THC), and appears to have anti-convulsive action in animal models.

Insys’ pharmaceutical CBD is over 99.5% pure cannabidiol. It is synthesized to be chemically identical to the CBD extracted from cannabis, and is produced in a controlled environment. The FDA issued a Drug Master File (DMF) to Insys for its CBD active pharmaceutical ingredient in May 2014.

About Infantile Spasms

An infantile spasm (IS), also known as West Syndrome, is a specific type of seizure seen in an epilepsy syndrome of infancy and childhood. West Syndrome is characterized by infantile spasms, developmental regression, and a specific pattern on electroencephalography (EEG) testing called hypsarrhythmia (chaotic brain waves). The onset of infantile spasms is usually in the first year of life, typically between 4-8 months. The seizures primarily consist of a sudden bending forward of the body with stiffening of the arms and legs; some children arch their backs as they extend their arms and legs.(1)

About Insys Therapeutics, Inc.

Insys Therapeutics is a specialty pharmaceutical company that develops and commercializes innovative drugs and novel drug delivery systems of therapeutic molecules that improve the quality of life of patients. Using proprietary sublingual spray technology and capabilities to develop pharmaceutical cannabinoids, Insys addresses the clinical shortcomings of existing commercial products. Insys currently markets two products: Subsys(R), which is sublingual Fentanyl spray for breakthrough cancer pain, and a generic version of Dronabinol (THC) capsules. The Company recently submitted a New Drug Application to the U.S. Food and Drug Administration for Dronabinol Oral Solution, a proprietary, orally administered liquid formulation of dronabinol that Insys believes has distinct advantages over the current formulation of dronabinol in soft gel capsule. Insys is developing a pipeline of sublingual sprays, as well as pharmaceutical cannabidiol.

Subsys(R) is a registered trademark of Insys Therapeutics, Inc.

Forward-Looking Statements This press release contains forward-looking statements, including statements regarding our expectations related to our plan to pursue the development of treatments for IS related to epilepsy, our expectations related to the timelines for our pharmaceutical cannabidiol (CBD) candidate[s], the potential benefits of our pharmaceutical CBD therapies to patients, our expectations in connection with our manufacturing capabilities with respect to our DEA-inspected facility in Round Rock, Texas and out belief that our Dronabinol Oral Solution has distinct advantages over the current formulation of dronabinol in soft gel capsule. These forward-looking statements are based on management’s expectations and assumptions as of the date of this press release, and actual results may differ materially from those in these forward-looking statements as a result of various factors, many of which are beyond our control. For a description of these risks facing the company, please see the risk factors described in our filings with the United States Securities and Exchange Commission, including those factors discussed under the caption “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2014 and any subsequent updates that may occur in our Quarterly Reports on Form 10-Q. Forward-looking statements speak only as of the date of this press release and we undertake no obligation to update or revise these statements, except as may be required by law.